1. Field of the Invention
This invention relates generally to optical scanners used to convert optical images into digital data for subsequent reproduction and/or manipulation, and more particularly to optical scanners used in conjunction with printers.
2. Description of the Related Art
Optical scanners have long been used to capture existing optical images so that they may be transferred, stored, or manipulated using a more convenient means, typically a digital computer. The scanner captures the image by illuminating the image with a light source and sensing reflected light. The presence or absence of reflected light at a particular point determines the image characteristics at that point. For a black and white image, the absence of reflected light indicates a black region, while the presence of reflected light indicates a white region. For gray scale images the intensity of the reflected light must also be measured to determine the intensity of the image. In the case of color, separate light sources are used to detect the presence or absence of each color component.
Although use of scanners has shown significant increase in the recent past, the commercial acceptance of the individual scanner has been limited by its cost and consumption of precious office space. Although not as expensive as many other computer peripherals, e.g., laser printers, the additional cost can be prohibitively expensive, especially if the device is used only by a single user.
In addition to the cost, the consumption of space by a scanner may also be prohibitive. The computer user already has a computer, a monitor, a printer, and possibly a fax machine. The computer user, faced with steadily shrinking office space, has been reluctant to include additional computer peripherals in the confines of the user's immediate office space, especially if the device is not used frequently. However, this is exactly what is required for commercial success of the scanner. Commonly, peripherals that are not in constant use are relegated to a common office area where the device is shared by all of the people in the office. The effect of relocating the peripheral away from the user produces a productivity loss, resulting from walking to and from the device, proportional to the number of times the user must use the device. Further productivity is lost when the device is currently in use by another person in the office. Recently, manufacturers have attempted to address these concerns by combining computer peripherals into so-called multi-function-peripherals (MFPs) incorporating one or more of the following: printer, copier, facsimile and scanner. Typically, these devices are based around an electrophotographic (EP) engine. The EP engine executes a process by which a polymer toner is transferred onto a print media and then fused onto the media. Electrophotographic engines are being used in black and white copiers, printers, and facsimiles and thus provide a good base for MFPs. Color EP engines are available but are considerably more expensive than black and white EP engines. As a result, color EP engines are used in only the most cost insensitive applications, e.g., color proofing, and, consequently, have not been used as a platform for MFPs.
The MFP has not been widely accepted by the marketplace. The primary reasons being, once again, cost and space. Although their cost is less than the combined cost of the devices purchased separately, the MFP is still too expensive for each computer user to own one, especially considering that most computer users already own one or more of the devices, most frequently a printer. In many cases, users own less expensive printers, such as an ink-jet printer, especially small business and/or home users who require color printing. In addition, the MFPs, because of their increased functionality, consume more space than any one of the devices separately. As a result, these devices, if purchased at all, are once again relegated to a large common area where the device is shared by the office at large, resulting in the aforementioned productivity losses.
Accordingly, a need remains for an inexpensive optical scanner that consumes a minimum amount of additional space which, moreover, can operate in conjunction with existing low-cost ink-jet printers.